Tooth surfaces are absorbent and can become stained or discolored by the use of tobacco products, eating or drinking certain foods and beverages (e.g., coffee, tea and red wine), the build up of dental plaque, the process of aging, diseases, trauma, medications, congenital conditions, and other environmental effects. Teeth are comprised of an inner dentin layer, an outer enamel layer and an acquired pellicle. The acquired pellicle is a proteinaceous layer derived from saliva that forms on the surface of tooth enamel.
Extrinsic and intrinsic staining of the teeth can occur. Extrinsic staining is staining of the acquired pellicle that can occur when compounds such as tannins and polyphenolic compounds come in contact with teeth during eating, drinking or smoking. These compounds then become trapped in and tightly bound to the proteinaceous layer on the surface of the teeth. Extrinsic staining can be removed by mechanical methods of tooth cleaning, such as brushing or flossing and by chemical cleaning methods. Even with regular brushing and flossing, rapid or slow accumulation can develop into noticeable intrinsic tooth discoloration. Intrinsic staining can be caused by staining compounds that penetrate the enamel layer and the dentin layer or can arise from sources within the tooth. Intrinsic staining is difficult to remove and cannot typically be removed by mechanical methods of tooth cleaning, but high chemical concentrations and/or prolonged chemical cleaning methods can be used to remove some or all of this type of staining.
White, unstained teeth are considered cosmetically desirable. Teeth can be whitened by, for example, mechanical cleaning methods, veneers that are placed over the teeth, and chemical bleaching.
While tooth whitening products are known in the art, these products are traditionally used by those seeking the cosmetic benefit of whiter teeth. However, there is a different population of consumers who desire whiter teeth and/or more oral benefits including cleaner teeth, healthier gums, and decreased oral malodor. Therefore, there is a desire to provide oral hygiene products that can deliver oral care benefits in addition to tooth whitening. Furthermore, oral hygiene time is typically limited and so there is a desire to deliver these oral care benefits quickly and conveniently as part of a daily oral hygiene regimen.